1. Field of the Invention
The present invention relates to a method, system, and program for managing client access to a shared resource.
2. Description of the Related Art
A storage manager software product, such as the International Business Machines Corporation (“IBM”) Tivoli Storage Manager, manages the backup and archiving of client application data at a central server. Multiple client computers may provide data to a server including the IBM Adstar Distributed Storage System (ADSM) or the Tivoli Storage Manager, to backup on a storage array, such as numerous hard disk drives or tape medium. Upon receiving the data, the storage manager product typically writes the data updates to a log file. If the system goes down, then any changes to the database can be reversed using the updates maintained in the log file to ensure that the system is consistent as of a specified point in time prior to the system failure.
After a client has transferred a certain amount of data, the storage manager then commits the client transactions to the storage device. Committed transactions can then be removed from the log file. After commitment, a client is ensured that the storage device is consistent with respect to the client as of the time of the most recent committed transaction. For instance, when a Tivoli Storage Manager client is in session with a Tivoli Storage Manager server and there is an interruption of any kind, the Tivoli Storage Manager server automatically rolls the session back to the last committed transaction.
In the current art, if there are numerous clients providing backup data to the storage manager, then the log file may become full. When the log file becomes full, the storage manager must take the server off-line to prevent any further backup operations because the log file cannot be used to store the updates for data recovery purposes in the event of a system failure.
For these reasons, there is a need in the art for managing access to network resources, such as a log file, in systems where multiple clients are competing for shared resources. Further, there is a need to manage the log file to prevent the log file from becoming full, which takes the server off-line.